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Circuit/System Testing

WARNING: This page is about a different car, the 2007 Buick LaCrosse and 2007 Buick Allure. However, it is still accessible from the selected car via links, so may be relevant.
  1. Ignition OFF, disconnect the harness connector at the ignition switch.
  2. Test for 11.8-12.2 volts between the 12-volt reference circuit terminal 6 and ground.
    • If less than the specified range, test the 12-volt reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.
    • If greater than the specified range, test the 12-volt reference circuit for a short to voltage. If the circuit tests normal, replace the BCM.
  3. Test for 11.8-12.2 volts between the 12-volt reference circuit terminal 4 and ground.
    • If less than the specified range, test the 12-volt reference circuit for a short to ground or an open/high resistance.
    • If greater than the specified range, test the 12-volt reference circuit for a short to voltage.
  4. Connect the harness connector at the ignition switch.
  5. Disconnect the harness connector C1 at the BCM.
  6. Install a jumper wire between the 12-volt reference circuit terminal 25 and the 12-volt reference circuit terminal in the BCM.
  7. With the ignition in the OFF position, test for 0 volts at the following circuit terminals:
    • Ignition 1 circuit terminal 22
    • Ignition 3 circuit terminal 23
    • Crank voltage circuit terminal 21
    • If greater than 0 volts, test the applicable circuit for a short to voltage. If all circuits test normal, test or replace the ignition switch.
  8. With the ignition in the ACCY position, test for 11.8-12.2 volts at the ignition 3 circuit terminal 23.
    • If less than the specified range, test the ignition 3 circuit for a short to ground or an open/high resistance. If the circuit tests normal, test or replace the ignition switch.
    • If greater than the specified range, test the ignition 3 circuit for a short to voltage. If the circuit tests normal, replace the ignition switch.
  9. With the ignition in the RUN position, test for 11.8-12.2 volts at the follow circuit terminals:
    • Ignition 1 circuit terminal 22
    • Ignition 3 circuit terminal 23
    • If less than the specified range, test the applicable circuit for a short to ground or an open/high resistance. If the circuits test normal, test or replace the ignition switch.
    • If greater than the specified range, test the applicable circuit for a short to voltage. If the circuit tests normal, replace the ignition switch.
  10. With the ignition in the CRANK position, test for 11.8-12.2 volts at the crank voltage circuit terminal 21.
    • If less than the specified range, test the crank voltage circuit for a short to ground or an open/high resistance. If the circuit tests normal, test or replace the ignition switch.
    • If greater than the specified range, test the crank voltage circuit for a short to voltage. If the circuit tests normal, test or replace the ignition switch.
  11. If all circuits test normal, test or replace the BCM.
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